Question

Gurpreet sells two watches for 1995 each ,gaining 15% on one and losing 15% on one the otger .find his gain or loss per cent in the whole transaction

Answer 1

SP of lst watch = ₹1,955
Gain = 15 %
CP = SP×100/100+Gain %
= 1,955×100/100+15
= 1,955×100/115
= ₹1,700
SP of 2nd watch = ₹1,955
Loss = 15 %
CP = SP×100/100-Loss %
= 1,955×100/100-15
= 1,955×100/85
= ₹2,300
Total CP of both watches = ₹(1,700+2,300)
= ₹4,000
Total SP of both watches = ₹(1,955×2)
= ₹3,910
Loss = CP - SP
= ₹(4,000-3,910)
= ₹90
Loss % = Loss/CP × 100
= 90/4,000×100
= 2.25 %.

Answer 2

Solutions :-

We have,
Gurpreet sells two watches for Rs 1995 each

Find the cost price of one watch at gain of 15% :-

C.P = (S.P × 100)/(100 + gain)
= (1995 × 100)/(100 + 15)
= 199500/115
= 1734.78

Find the cost price of other watch at loss of 15% :-

C.P = (S.P × 100)/(100 - loss)
= (1995 × 100)/(100 - 15)
= 199500/85
= 2347.05

Now,
We have,

Selling price of two watch = Rs (1995 + 1995) = Rs 3990
Cost price of two watch = Rs (1734.78 + 2347.05) = Rs 4081.83

Cost Price > Selling price

Loss = C.P - S.P
= Rs (4081.83 - 3990)
= Rs 91.83

Loss % = (loss × 100)/ C.P %
= (91.83 × 100)/4081.83 %
= 9183/4081.83 %
= 2.25 %

Answer : His loss percentage in the whole transaction = Rs 2.25%